The total U.S. consumption of electricity in a particular year was 5.0 x 10^12 kilowatt-hours. What is the mass equivalence of this amount of energy? Show all calculations leading to an answer.

Question

How would I solve it?

Answer 1

E = m c^2
c^2 = (3*10^8)^2 = 9 * 10^16

E = 5 * 10^15 watts * 3600 seconds
= 18 * 10^18 Joules

m = 18*10^18/9*10^16
= 2 * 10^2
= 200 Kg
about two big people mass :)

Answer 2

could you explain how you got your answer..step by step

Answer 3

I thought I did :)

surely you can google E = m c^2
(Albert Einstein)
there
E is in Joules which is watt seconds
c is speed of light, about 3*10^8 meters/second
an hour is 3600 seconds
a kilowatt is 1000 watts which is 1000 Joules/second

Answer 4

thank you so much! :)